Differences

This shows you the differences between two versions of the page.

--- intro_oled [2026/04/02 09:43] – [PMOLED (Passive-Matrix OLED)] sophie
+++ intro_oled [2026/04/02 16:12] (current) – [physics behind OLEDs] sophie
@@ Line 1: / Line 1: @@
-# OLED (Organic Light Emitting Diode) screens
+# OLED (Organic Light Emitting Diode) screen
+## physics behind OLEDs
+OLEDs are emitting light thanks to the electron-hole recombination principle.
+OLEDs are made of:
+  * an organic emissive layer in which electron and hole recombine: electrons being excited by an electrical field unexcite themselves by emitting a photon
+  * (optional: only for multilayer OLEDs) a hole transport and electron transport layer above and below the emissive layer, respectively: to improve the movment of holes and electrons towards the emissive layer
+  * (optional: only for multilayer OLEDs) a hole injection layer to improve the movement of hole from the anode towards the hole transport layer
+  * two electrodes: an anode under the hole injection layer and a cathode on top of the electron transport layer
+  * a subtrate - usually glass - under the anode
+{{:capture_d_ecran_2026-04-02_160915.png?direct&400 |}} (([Joëlle Rault-Berthelot, Cyril Poriel, Diodes électroluminescentes organiques : quatre technologies différentes, 2021](https://univ-rennes.hal.science/hal-03388539/file/Rault-Berthelot-2021-%20OLED%204%20technologies%20diff%C3%A9rentes.pdf)))
+s
 ## Types of rigidity: flexible vs. rigid OLED screens
@@ Line 24: / Line 37: @@
 ### blue OLED with colour converting materials
 ## Type of stack structures: top vs. bottom emission
 ### top emission OLED
   * most used technology because less constraints on materials (no need for backplane to be transparent)
   * cathode must be transparent (Ag material)
-{{ :capture_d_ecran_2026-04-02_092931.png?direct |}
+{{ :capture_d_ecran_2026-04-02_092931.png?direct |}}
-}
 ### bottom emission OLED
   * this technology emerged first,